Objective automated color matching between input and output devices

ABSTRACT

An image processing apparatus is constructed by a setting circuit for manually setting a first color processing parameter, a first color processing circuit for performing a first color process by using the first color processing parameter, a storing circuit for storing a second color processing parameter set in correspondence to the first color processing parameter as a reference value, and a second color processing circuit for performing a second color process different from the first color process by using the second color processing parameter, wherein in case of making the second color processing circuit function, the first color processing parameter is set to the reference value.

CROSS REFERENCE TO RELATED APPLICATION

This application is a division of Application Ser. No. 08/724,481, filedFeb. 17, 1998, now U.S. Pat. No. 6,118,455, issued Sep. 12, 2000.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to image processing apparatus and method forperforming a color process.

2. Related Background Art

In recent years, it has become know that problems exist such thatvarious color reconstructions are performed due to a difference of acoloring mechanism for each input/output device or a difference of acoloring material to be used. This is due to a spread of networks and anenlargement of a demand for a color product and that a color matchingfunction differs for each kind of apparatus. There is a color managementsystem (CMS) which is known as a technique which is highlighted to solvethose problems. At present, to solve the problems, a process is executedfor matching the colors of input and output images by connecting thesystem to a computer and performing a data conversion using profile dataformed every input/output equipment by using a software (CMS software).

Even if the same signal is inputted, the same color is not alwaysoutputted due to a difference of the device. Therefore, informationregarding characteristics of input/output signals in input/outputequipment which was set in a reference state in order to suppress thecharacteristics of each device has been stored in the profile data.Input/output characteristics of the signal of the device are distinct bythe profile data of each device and by correcting by using the profiledata, the colors can be matched irrespective of the device.

The data conversion will now be described with reference to FIG. 13. Inthe diagram, device characteristics data regarding input equipment hasbeen stored in input equipment profile data 101. Device characteristicsdata regarding output equipment has been stored in output equipmentprofile data 107.

A color signal obtained from the input equipment is converted by a dataconversion unit 106 by using the input equipment profile data 101. Theconverted data is a color signal which doesn't depend in each device. Infurther another data conversion unit 112, the data is converted into acolor signal suitable for each output equipment by using the outputequipment profile data 107 and is outputted by using such a colorsignal.

At present, input/output equipment such as monitor, printer, scanner, orthe like which is most frequently used has a function for changing thecolor or brightness in accordance with a taste of the user. The monitorgenerally has a knob to adjust the brightness and contrast. To obtain apreferable image in consideration of a fatigue of the eyes, the user canadjust the brightness of the monitor by freely moving the knob. In amonitor which can perform a further advanced correction, a formation ofa gamma table, a change in color temperature of the monitor, and thelike can be performed.

In a manner similar to the above, there is also a printer having thecorrecting function to obtain a desired color of the user by a methodsuch that an output balance of colors is adjusted, an LUT is formed, orthe like.

As mentioned above, when input/output equipment which can be adjusted bythe user is used, there occurs a problem such that by the execution ofthe adjustment by the user, a state of the input/output equipment whenthe profile data is formed and a state of the equipment when data isactually inputted or outputted are different, so that an accurate colormatching cannot be performed.

Such a problem also occurs in the color management system for performinga color matching process according to an illumination light, namely, acolor managing technique which has been proposed in recent years.

A construction in the case where an image of an original is read by animage scanner and the read image is displayed on a monitor screen and anambient light is considered will now be described. FIG. 14 shows aschematic constructional block diagram. An image scanner 510 reads outthe image of the original and outputs the read image data in an (R, G,B) form. A scanner color conversion device 512 converts an output signalof an RGB colorimetric system of the scanner 510 into a standardcolorimetric system (XYZ colorimetric system) with reference to ascanner profile 514 which has previously been formed from image readingcharacteristics of the image scanner 510.

A signal conversion device 516 corrects an output of the conversiondevice 512 in consideration of an ambient light in accordance withambient color information which is supplied from the ambient lightsensor 518 to detect color components or a color distribution of theambient light.

In accordance with a monitor profile 522 which reflects coloringcharacteristics of a monitor display (hereinafter, abbreviated to amonitor) 524 to be used, a monitor color conversion device 520 convertsthe output signal of the XYZ colorimetric system of the signalconversion device 516 into values of an RGB space in consideration ofthe coloring characteristics of the monitor 524 and supplies the outputsignal to the monitor 524.

An environment where the image is observed will now be simply explainedwith reference to FIG. 15. A printed matter (original) 530 is read bythe image scanner 510 and the read image is displayed as an image(original image) 532 on the screen of the monitor 524. The illuminationlight from a fluorescent light or the like illuminates an ambientportion as an ambient light 534. The ambient light sensor 518 is putonto the monitor 524, a printer, or a computer main body and detects acolor distribution or color components of the ambient light 534. Theoriginal image 532 is generally displayed on the screen of the monitor524 so as to be overlaid on a background color (color of the screen)536. Therefore, the user simultaneously looks at both of the backgroundcolor 536 and the original image 532 and recognizes the color of theoriginal image 532.

The ambient light 534 changes depending on a situation. According to theexisting color managing technique, the ambient light 534 is detected bythe ambient light sensor 518 and, in accordance with the detectioninformation, the signal conversion device 516 corrects an output of thescanner color conversion device 512, namely, the color signal of thestandard colorimetric system. Thus, the coloring of the original image532 which is displayed on the screen of the monitor 524 is adjusted inaccordance with the ambient light. Namely, a colorimetrologicalcoincidence is realized.

Although the colors of the same value on the standard color spaceinherently ought to be seen as a same color, in the case where bothcolors are a color of the monitor (light source color) and a color ofthe printed matter (object color) and even if they have the same valueon the standard color space, they cannot be seen as a same color for thehuman eyes due to a difference of the visual environment, mode, or thelike. As for such a problem, the following correcting techniques havealso been proposed in order to enable the human being to perceive themas a same color by observing with the eyes.

It is considered that when observing colors, the human being uses whiteas a reference and recognizes all of the colors by comparing with white.It is now considered a case, as an example, of observing a monitordisplay image put under a certain ambient light and a printed matter putunder the same or a different ambient light. There are a number of whitecolors which should be reference colors such as white of the monitorscreen, white of the environmental light, white of a paper illuminatedby the environmental light, and the like. It is possible to regard suchthat the colors are observed by using a white color adapted to such anumber of white colors at a certain ratio as a reference. A methodwhereby by calculating reference white and converting the colors of allof the image by setting such white as a reference, observation colorsare mutually matched is considered. Actually, when reference white iscalculated, one adaptation ratio of white of the monitor screen underthe fluorescent light to the ambient light is determined and referencewhite is calculated by using such an adaptation ratio.

As shown in FIG. 15, when observing the original image 532 which isdisplayed on the screen of the monitor 524, both of the original image532 and the ambient color (background color) 536 simultaneously enterthe eyes. Since human being recognizes the color by a comparison withthe circumstances, it is known that if the colors displayed in thecenter portion are the same and the background colors are different, thecolors of different impressions are perceived. Therefore, even in caseof displaying the same image, if the background color differs, the colorof the display image is recognized as a different color.

SUMMARY OF THE INVENTION

The invention is made in consideration of the above points and it is anobject of the invention to realize a highly-accurate color matching.

Particularly, an object of the invention is to enable an effect of apreset color process to be most efficiently derived.

To accomplish the above object, according to the invention, there isprovided an image processing apparatus comprising: setting means formanually setting a first color processing parameter; first colorprocessing means for performing a first color process by using the firstcolor processing parameter; storing means for storing a second colorprocessing parameter which has been set in correspondence to the firstcolor processing parameter as a reference value; and second colorprocessing means for performing a second color process different fromthe first color process by using the second color processing parameter,wherein when the second color processing means is made to function, thefirst color processing parameter is set to the reference value.

Another object of the invention is to provide a highly-accurate colormatching on the basis of an application of the user.

To accomplish the above object, according to the invention, there isprovided an image processing apparatus having first and second colormatching modes for performing different color matching processes,comprising: selecting means for selecting the color matching mode on thebasis of an instruction of the user; and setting means for setting abackground color on a display screen to a predetermined color when thesecond color matching mode is selected by the selecting means.

The above and other objects and features of the present invention willbecome apparent from the following detailed description and the appendedclaims with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram regarding an image processing apparatusaccording to embodiment 1;

FIG. 2 is a flowchart for image processes according to embodiment 1;

FIG. 3 is a constructional diagram of an image processing systemaccording to embodiment 2;

FIG. 4 is a block diagram showing an example of an image processingsystem according to a modification of embodiment 1;

FIG. 5 is a block diagram showing an example of an image processingsystem according to a modification of embodiment 1;

FIG. 6 is a flowchart for image processes according to embodiment 2;

FIG. 7 is a schematic constructional block diagram of an imageprocessing apparatus according to embodiment 3;

FIG. 8 is a schematic diagram showing an arrangement of blocks in theembodiment shown in FIG. 7;

FIG. 9 is a schematic constructional block diagram in a signalconversion device 16;

FIG. 10 is a schematic diagram showing the relations among an ambientlight, white and a background color of a monitor, and reference white;

FIG. 11 is a schematic constructional block diagram of a modification;

FIG. 12 is an operating flowchart for the modification shown in FIG. 11;

FIG. 13 is a block diagram of an image processing apparatus according tothe prior art;

FIG. 14 is a schematic constructional block diagram of the prior art;and

FIG. 15 is a diagram for explaining a general use environment.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Embodiments according to the invention will now be described hereinbelowwith reference to the drawings.

[Embodiment 1]

Embodiment 1 relates to an example when the invention is applied to animage processing apparatus having an input unit, an output unit, and acolor matching processing function.

According to a color matching process, a data conversion is executed soas to equalize a color reconstruction irrespective of a device on thebasis of input/output profiles showing input/output characteristicswhich are different for every input/output device.

FIG. 1 shows a block diagram of the image processing apparatus accordingto embodiment 1.

Information regarding characteristics of input/output signals in eachinput/output device which was set into a reference state has been storedin profile data of the input unit and output unit.

Further, a parameter regarding the reference state of an input unit 104at the time of formation of the input unit profile is added as areference parameter 102 to the input equipment profile data. Similarly,a reference parameter 108 at the time of the formation of an outputequipment profile is added to the output equipment profile data. Forexample, in case of a monitor which is used as input/output equipment,parameters regarding an image adjustment such as gamma characteristics,contrast, brightness, color temperature of white, and the like have beenstored in the reference parameter.

As an example of a method of forming the profile data, in case of aprinter, first, the apparatus is set to a reference state and areference sample in which a certain known input signal is outputted andcolor characteristics of the outputted sample are measured. The relationof the input/output signals is stored as profile data.

Device characteristics data regarding the input unit 104 has been storedin the input equipment profile data 101. Device characteristics dataregarding an output unit 110 has been stored in the output equipmentprofile data 107.

User adjustment parameter storage units 103 and 109 exist in theinput/output units and parameters regarding the image adjustmentincluding values which were freely set by the user by using knobs, menubars, and the like provided for a user adjustment unit 105 and outputparameter adjustment unit 111 have been stored in the storage units 103and 109.

When the input unit or output unit is solely used without using CMSsoftware, ordinarily, an image is inputted or outputted by using theparameters stored in the user adjustment parameter storage units.

However, when the color matching process is executed, in order torealize a color reconstruction of high quality, it is necessary to set areference state when each profile data is formed.

Namely, it is necessary to set the parameters of the input/output unitsin correspondence to the input/output profile data.

For this purpose, which one of the user adjustment parameter 103 and thereference parameter 102 at the time of the formation of the inputequipment profile should be used needs to be decided by a color matchingprocessing condition setting unit 124 in accordance with theinput/output environment of the image.

A flow of processes according to embodiment 1 will now be describedhereinbelow with reference to FIG. 2.

First, whether or not the color matching process is executed is set bythe color matching processing condition setting unit 124 in a consoleunit 125 (S10).

When the color matching process is executed, the processing parametersin the input unit 104 and output unit 110 are set to the referencevalues when the profiles are formed (S20).

An inputting process is executed on the basis of the reference valuesset in the input unit 104, thereby obtaining input image data (S30).

As mentioned above even if the user adjustment parameters are used, incase of matching the colors of input and output images by using thecolor matching process, the reference parameter 102 which has previouslybeen added to the input equipment profile data is used in place of theuser adjustment parameter 103. At this time, the user adjustmentparameters are rewritten and the control of the input unit can beperformed or the control of the input unit can also be directlyperformed by using the reference parameter irrespective of the useradjustment parameters. As mentioned above, the input image data isobtained by the input equipment set in the reference state.

In the data conversion unit 106, the input image data is subjected to adata conversion process 1 for converting into data (device independentsignal) which doesn't depend on the device on the basis of the inputequipment profile data 101 (S40).

In the data conversion unit 112, a data conversion process 2 forconverting into output image data suitable for an output device isexecuted on the basis of the output equipment profile data 107 (S50).

Namely, in the data conversion process 1, the input image data dependingon the input unit is converted into the device independent data by usingthe input equipment profile data. In the data conversion process 2, thedevice independent data is converted into output image data whichdepends on the output unit by using the output equipment profile data.

In a manner similar to the input unit, even if the user adjustmentparameters have been set, in case of matching the colors of the inputand output images by using the color matching process, the referenceparameter 108 which has previously been added to the output equipmentprofile data and has been set in step S20 is used in place of the useradjustment parameters 109, thereby obtaining output image data from theoutput unit 110 set in the reference state.

On the other hand, when a mode such that the color matching process isnot executed is set in step S10, the parameters of the input unit andoutput unit are arbitrarily manually set in accordance with anapplication of the user by using the user adjustment unit 105 and outputparameter adjustment unit 111 of a console unit 25 (S70).

When the parameters of the input unit and output unit have been presetin accordance with the application of the user, those parameters canalso be used.

An input process is executed in the input unit and an output process isexecuted in the output unit in accordance with the set parameters (S80and S90).

Each unit of the image processing apparatus is controlled by a CPU 121connected through a CPU bus 120.

The CPU 121 controls each of the above units by using a RAM 123, as awork memory, on the basis of, for example, a program to executeprocesses shown in FIG. 2 stored in a ROM 122 in accordance with thesetting of the console unit 125.

According to embodiment 1, when the color matching process is executed,since the input and output processes are executed in the input/outputunits by parameters suitable for the input/output equipment profileswhich are used for the color matching processes which are executed bythe data conversion units 106 and 112, an effect of the CMS process canbe most efficiently derived.

That is, the colors can be matched irrespective of the input/outputdevices.

When the color matching process is not executed, an arbitrary processcan be performed on the basis of a a choice by the user.

[Modification 1]

As a modification, an example in which the invention is applied to animage processing system as shown in FIG. 3 will now be described.

The image processing system is constructed by: input equipment 204 andoutput equipment 210 corresponding to the input unit 104 and output unit105 in the embodiment 1; and a computer 200 for performing the colormatching process.

An example in the case where the user adjustment parameters exist in amemory of the computer for controlling instead of the input/outputequipment will now be described hereinbelow with reference to FIG. 4.

Portions similar to those in embodiment 1 are designated by the samereference numerals.

In a manner similar to embodiment 1, when an image is inputted, whetherthe user adjustment parameters 103 are used or the parameters are set tothe reference parameter 102 when each profile is formed is firstdetermined in accordance with input/output environment of the image.Both of the user adjustment parameters and the reference parameter havebeen stored in the memory of the computer for controlling. When thecolors of the input and output images are matched by a CMS (colormanagement system) software, in a parameter selection unit 301, thereference parameter 102 added to the input equipment profile data isselected. On the basis of the selected parameter, the input equipment isset into the reference state by an input equipment control unit 302. Inthe other case where the CMS software is not used, the user adjustmentparameters 103 adjusted by the user are selected and the input equipment204 is controlled by using the user adjustment parameters. Image data isobtained by such input equipment.

Even in the data conversion, a conversion similar to that in embodiment1 is executed. The control of the output equipment is also substantiallythe same as that for the input equipment. Either one of the useradjustment parameters 109 and reference parameter 108 is selected inaccordance with the input/output environment of the image. An outputimage is derived from output equipment 210 controlled by using theselected parameter.

In the image processing system shown in FIG. 3, the reference parameterhas been added to the input/output equipment profile data. However, asshown in FIG. 5, both of the user adjustment parameters 103 and 109 andthe reference parameters 102 and 108 can also be stored into parameterstorage units 401 and 402 of the input/output equipment by disconnectingfrom the input/output equipment profile data, respectively. It is alsopossible to arbitrarily select both of them in accordance with theinput/output environment and to obtain an image by the input/outputequipment controlled by the selected data.

Although the storing locations of the data have been limited in theabove embodiment, the invention is not limited to the example as shownin the embodiment but the invention can also be sufficiently applied toa combination of them or a case where the storing positions of the useradjustment parameters and a reference parameter are other than thelocations mentioned in the embodiment.

That is, the user adjustment parameters can also be stored in theinput/output equipment main bodies.

[Embodiment 2]

In the foregoing embodiment 1, when the color matching processing modeis set, the user cannot set a user processing parameter.

Therefore, for example, when the user wants to finely adjust the imagegenerated by the color matching process, the user has to set an ordinarymode in which the color matching process is not executed and to setparameters from the beginning.

In embodiment 2, an example in which an image can be finely adjusted fora color matching processing result will now be described with referenceto FIG. 6.

In FIG. 6, substantially the same processing steps as those in theembodiment 1 are designated by the same processing step numbers andtheir descriptions are omitted.

In FIG. 6, processes in steps S110 to S160 are added to the processes inthe embodiment 1 in order to perform the fine adjustment mentionedabove.

When the CMS processing mode is set in step S20, the color matchingprocess (S10 to S50) is executed in a manner similar to embodiment 1 andthe image data which was color matching processed is stored into the RAM123.

An image is outputted by using the reference parameter by the outputunit 110.

Whether or not the output image is satisfactory is confirmed by the eyes(S120).

When the user is satisfied with the output image, the processing routineis finished.

On the other hand, when the user cannot satisfy the output image, inorder to perform the fine adjustment, the parameters of the output unitare set by using the output parameter adjustment unit 111 (S130).

The image data which was CMS processed and stored in the RAM 123 is readout and an image is outputted by using the set parameters (S140).

The processes in steps S120 to S140 are repeated until a satisfactoryoutput image can be obtained.

Each of the above embodiments has been shown and described on theassumption that, as for the selection between the user adjustmentparameters and the reference parameter, when the color of the image iscontrolled by the CMS software, the reference parameter is selected and,in the other cases, the user adjustment parameters are used. However, itis also possible to automatically select the parameters or toarbitrarily select either one of those parameters in accordance with adesire of the user case by case.

Further, although the case where the number of reference parameters whenthe profile is formed is set to one parameter has been shown above, itis also possible to construct in a manner such that there are aplurality of reference parameters corresponding to the user adjustmentvalues and a reference parameter at the time of control is newly formedas interpolation data of them.

Although the embodiments have been described above with respect to theinput/output equipment, the invention can also be applied to any othervarious combinations such as (scanner and monitor), (monitor andprinter), and the like as a combination of the input/output equipment.

[Embodiment 3]

The embodiment 3 of the invention will now be described in detailhereinbelow with reference to the drawings.

Embodiment 3 of the invention applied to a copying apparatus with amonitor for displaying an original image and a previewer havingfunctions for a selection of an output portion, an edition of a color,and the like on a monitor screen will now be described. FIG. 7 shows aschematic constructional block diagram of such a copying apparatus. FIG.8 shows a schematic block diagram showing an arrangement of functionalblocks in FIG. 7. The same component elements in FIGS. 7 and 8 aredesignated by the same reference numerals.

An image of an original is read by the image scanner 10. The imagescanner 10 outputs the read image data as an RGB signal. The scannercolor conversion device 12 converts the output signal of the RGBcolorimetric system (color system) of the scanner 10 into values of theXYZ colorimetric system in consideration of the reading characteristicsof the image scanner 10 in accordance with the scanner profile 14 whichhas been prepared in accordance with the reading characteristics of theimage scanner 10. An output of the color conversion device 12 is astandard color signal which doesn't depend on the image input device. Itwill be obviously understood that the standard color space is notlimited to the XYZ colorimetric system and another arbitrarycolorimetric system can be used so long as it can absorb a devicedependence.

Data regarding the color characteristics of the scanner 10 has beenstored in the scanner profile 14. Specifically speaking, a colorconversion matrix from RGB to XYZ or a lookup table (LUT) has beenstored.

The signal conversion device 16 corrects an output of the conversiondevice 12 in accordance with ambient color information which is suppliedfrom the ambient light sensor 18 for detecting color components or acolor distribution of the ambient light and white information andinformation of a background color of the monitor 24 to display the readimage. In the embodiment, the white information and the information ofthe background color of the monitor 24 are supplied from the monitorprofile 22 having the coloring characteristics of the monitor 24.

In accordance with the coloring characteristics information from themonitor profile 22, the monitor color conversion device 20 converts theoutput signal of the XYZ colorimetric system of the signal conversiondevice 16 into the RGB values in consideration of the coloringcharacteristics of the monitor 24 and supplies the output signal to themonitor 24. The monitor 24 displays the image of the original as apreview image.

Data regarding the coloring characteristics of the monitor 24,specifically speaking, a color temperature and a light emissionluminance of the monitor 24, a chromaticity value of a fluorescentmaterial, color conversion information from the standard color space tothe device dependence color signal, and the like have been stored in themonitor profile 22. The monitor background color information which issupplied from the monitor profile 22 to the signal conversion device 16includes background color information which is at present displayed bythe monitor 24 and the background color information when the monitorprofile 22 is formed.

In accordance with the characteristics information from a printerprofile 28 having coloring characteristics of the printer 30, theprinter color conversion device 26 converts the output signal of the XYZcolorimetric system of the signal conversion device 16 into a CMYKsignal in consideration of the coloring characteristics of the printer30 and supplies the output signal to the printer 30. The printer 30prints and outputs the image of the original onto a recording paper inaccordance with the color signal from a color conversion device 26.

As shown in FIG. 8, the scanner color conversion device 12 is enclosedin a scanner unit 32. The signal conversion device 16, monitor colorconversion device 20, printer color conversion device 26, and printer 30are enclosed in a printer unit 34. The monitor 24 is put on an upperportion of the scanner unit 32. The ambient light sensor 18 is arrangedbeside the monitor 24.

FIG. 9 shows a schematic constructional block diagram in the signalconversion device 16. Adaptation ratios corresponding to one or two ormore environments which are presumed in the case where the ambient lightis a predetermined standard light source (A, C, D93, D65, D50, F, etc.)have been stored in an adaptation ratio storage 40. An adaptation ratioalso corresponding to a background color (for example, gray scale) whenan image is seen has also been stored in the adaptation ratio storage40. An adaptation ratio determination device 42 selects the adaptationratios corresponding to the present ambient light and the backgroundcolor of the monitor from the adaptation ratio storage 40 in accordancewith the ambient light information from the ambient light sensor 18 andthe monitor white information and the monitor background colorinformation from the monitor profile 22 and supplies them to a referencewhite calculation device 44.

The reference white calculation device 44 calculates reference whitesuitable for the ambient light and an observation environment such ascolor temperature, background color, and the like of the monitor 24 inaccordance with the adaptation ratios from the adaptation ratiodetermination device 42, the ambient light information from the ambientlight sensor 18, and the monitor white information and monitorbackground color information from the monitor profile 22. Itscalculating method will be described in detail hereinlater.

An image conversion device 46 converts signals (Xi, Yi, Zi) from thescanner color conversion device 12 in accordance with reference white(Xw, Yw, Zw, xw, yw) calculated by the reference white calculationdevice 44 and generates signals (Xo, Yo, Zo) of the XYZ colorimetricsystem.

FIG. 10 is a schematic diagram showing the relation among the ambientlight, white and background color of the monitor, and reference white.The ambient light is based on the reference light source. FIG. 10 showsreference white colors as an example with respect to two backgroundcolors. An output of the ambient light sensor 18 can be any one of thespectral data, color signals of XYZ, RGB, or the like, and manual inputof those color signals. In FIG. 10, the ambient light information isshown as a reference light source W. The monitor white information fromthe monitor profile 22 is the color temperature, luminance value,chromaticity value, etc. and is shown as a monitor white point V in FIG.10.

As described above, when observing the image which is displayed on themonitor screen, it is considered that the human being isn't perfectlyadaptive to only monitor white but is adaptive to both of monitor whiteand the ambient light at a certain ratio. As shown in FIG. 10,therefore, reference white serving as a color observing reference islocated between monitor white and the ambient light (reference lightsource). It is now assumed that an adaptation ratio to monitor white isset to s, an adaptation ratio to the ambient light is set to 1−s, theambient light information which is obtained from the ambient lightsensor 18 is set to Wx, Wy, Wz, wx and wy, monitor white signals whichare obtained from the monitor profile 22 are set to Vx, Vy, Vz, vx, andvy, and reference white signals to be calculated are set to Xw, Yw, Zw,xw, and yw, respectively. Thus, Xw, Yw, Zw, xw, and yw can be calculatedby the following equations (1) and (2). Namely, with regard to threestimulus values,Xw=(1−s)·Wx+s·VxYw=(1−s)·Wy+s·VyZw=(1−s)·Wz+s·Vz  (1)With regard to the chromaticity values,xw=(1−s)·wx+s·vxyw=(1−s)·wy+s·vy  (2)

Since s depends on the ambient light at the time of the imageobservation and the background color of the monitor 24, the adaptationratio (s:1−s) changes depending on the ambient light and the backgroundcolor of the image. In association with it, the reference white pointalso changes every ambient light and background color. For example, whenthe background color is changed from black to white at a gray scalelevel, as the background color approaches black, the adaptation ratio tothe ambient light increases irrespective of the color temperature of themonitor 24 and ambient light.

It is, therefore, necessary to decide the adaptation ratio in accordancewith not only the ambient light but also the background color to beobserved. In the embodiment, by deciding as mentioned above, the optimumreference white point is calculated.

A method of converting the whole image on the basis of the referencewhite signal calculated in this manner will now be described.

The image which is displayed on the monitor screen is observed on thebasis of reference white calculated as mentioned above. On the otherhand, the printed matter is adaptive to white of the paper or white ofthe ambient light. It is now assumed that the reference white is set toXw, Yw, and Zw, white of the ambient light is set to Wx, Wy, and Wz, theimage signals (input signals of the image conversion device) which areinputted from the scanner color conversion device 12 to the signalconversion device 16 are set to Xi, Yi, and Zi, and the image signalswhich are outputted from the image conversion device 46 of the signalconverting apparatus are set to Xo, Yo, and Zo. The following equation(3) as a modification of Von Kreis's equation is satisfied. Namely,$\begin{matrix}{\begin{pmatrix}{{Xo}/{Xw}} \\{{Yo}/{Yw}} \\{{Zo}/{Zw}}\end{pmatrix} = \begin{pmatrix}{{Xi}/{Wx}} \\{{Yi}/{Wy}} \\{{Zi}/{Wz}}\end{pmatrix}} & (3)\end{matrix}$By modifying the equation (3), the following equation (4) is obtained.$\begin{matrix}{\begin{pmatrix}{Xo} \\{Yo} \\{Zo}\end{pmatrix} = {\begin{pmatrix}{Xi} \\{Yi} \\{Zi}\end{pmatrix}\begin{pmatrix}{{Xw}/{Wx}} \\{{Yw}/{Wy}} \\{{Zw}/{Wz}}\end{pmatrix}}} & (4)\end{matrix}$

The following equation (5) can be also used by also including thecontrast conversion of the image in consideration of the visual sensecharacteristics of the human being into the equation (4). Namely,$\begin{matrix}{\begin{pmatrix}{{Xo}/{Xw}} \\{{Yo}/{Yw}} \\{{Zo}/{Zw}}\end{pmatrix} = \begin{pmatrix}{{Xi}/{Wx}} \\{{Yi}/{Wy}} \\{{Zi}/{Wz}}\end{pmatrix}^{\gamma}} & (5)\end{matrix}$By modifying the equation (5), $\begin{matrix}{\begin{pmatrix}{Xo} \\{Yo} \\{Zo}\end{pmatrix} = {\begin{pmatrix}{{Xi}/{Wx}} \\{{Yi}/{Wy}} \\{{Zi}/{Wz}}\end{pmatrix}^{\gamma}\begin{pmatrix}{Xw} \\{Yw} \\{Zw}\end{pmatrix}}} & (6)\end{matrix}$

The monitor color conversion device 20 converts the image signals Xo,Yo, and Zo obtained as mentioned above from the XYZ colorimetric systemto the RGB colorimetric system in accordance with the conversioninformation from the monitor profile 22.

By such a color matching process, color tones of a source image and anoutput image can be matched. Particularly, by obtaining the referencewhite signal also in consideration of the background color, a good colormatching process can be performed.

In the above embodiment, when the adaptation ratio (s:1−s) or s isdecided, the adaptation ratio has been changed in accordance with bothof the ambient light and the background color. However, the adaptationratio can be also set in accordance with the observation environmentsuch as color temperature of the monitor, reflected light from themonitor, or the like.

FIG. 11 shows a schematic constructional block diagram of a modificationof the above embodiment. In the modification, the user can select thesetting of a color process. Specifically speaking, in case of performingthe color process at a high precision, a predetermined background coloris displayed on the monitor 24 and both of the display image and thebackground color, namely, the whole screen of the monitor 24 iscontrolled, thereby more accurately matching the original image to bedisplayed on the monitor 24 and the original image which is seen.Reference numeral 50 denotes a color processing setting device to set acolor processing method. There is a mode to use the present backgroundcolor of the monitor 24 as is and a mode to display a specificbackground color which has previously been selected. The user selectsthe latter mode when he wants to perform a color management at a highaccuracy.

FIG. 12 shows a flowchart of a main operation portion of themodification shown in FIG. 11.

By the color processing setting device 50, the user sets the colorprocessing method (color matching mode) to be executed by the signalconversion device 16 in accordance with an application (S1). It can beset by a menu bar or the like or can also be selected by pushing abutton. Further, it is also possible to determine the default in amanner such that the color managing process as described in theembodiment shown in FIG. 7 is performed and a highly-accurate colormanagement is executed in the other cases.

In case of the highly-accurate color management (S1), the backgroundcolor of the screen of the monitor 24 is set to a predetermined color(S5). In the case where the highly-accurate color management is notperformed (in case of the ordinary color management) (S1), the presentbackground color is maintained as is.

In order to perform the highly-accurate color management, it isnecessary to control the background color. Therefore, when a pluralityof windows are opened on the same screen, the other windows are hiddenby the background color. On the other hand, when the highly-accuratecolor management is not performed, processes can be executed in parallelwith reference to the other windows. The user, accordingly, sets thecolor processing method on the basis of the application (whether apriority is given to the precision of the color matching or not) in stepS1.

The subsequent processes are substantially the same as those in theembodiment shown in FIG. 7. The signal conversion device 16 sets theoptimum adaptation ratio from the ambient light information from theambient light sensor 18, the monitor white information, and thebackground color of the monitor and converts the output signal of thescanner color conversion device 12 in accordance with the referencewhite signal that is decided on the basis of the adaptation ratio (S2).The monitor color conversion device 20 converts the output signal of thesignal conversion device 18 from the XYZ colorimetric system to the RGBcolorimetric system (S3). The output image signal of the monitor colorconversion device 20 is displayed at a predetermined position on thescreen of the monitor 24 (S4).

In case of the highly-accurate color management, since the backgroundcolor is a predetermined color, the color matching can be performed at ahigher accuracy. As a background color in this case, for example, abackground color which has been set in the environment at the time ofthe formation of the profile or a standard environment at the time ofthe color observation or a background color that is optimum to everyenvironment has been prepared and the proper background color isselected among them in accordance with the present environment.

In the modification shown in FIG. 11, the decided background color hasbeen displayed only in case of selecting the highly-accurate colormanagement process. However, it is also possible to enable whether ornot the color management is performed to be selected and toautomatically display the determined background color in case ofexecuting the color management.

As for the background color of the monitor when the image is observed,the standard observing condition at the time of the formation of theprofile can be determined and such information can be stored into theprofile as mentioned above. However, in any case, it will be understoodthat when a luminance of the background color to be displayed on themonitor is lower than that of white in the observation image (white inthe print original), it is more desirable in case of matching both ofthe colors. White in the observation image (white in the print original)is obtained from a reflectance of the paper which has previously beenknown and the light source information derived from the ambient lightsensor 18. When the luminance of white in the print image is equal to orless than the luminance of the highest output of the monitor, it isdesirable to use the luminance of the background color having a valuesmaller than that of white in the observation image.

For example, when the image is observed in an environment in which theluminance of white in the observation image and the highest luminance ofthe monitor are equal and, after that, the luminance of the ambientlight of the room decreases, a phenomenon such that both of the colorscannot be matched because the background color of the monitor is toobright occurs. However, by setting the luminance of the monitorbackground color to be lower than that of white in the observationimage, an environment in which the color matching is more available canbe formed.

As means for obtaining the ambient light information, it is possible todetect the ambient light of the environment in which the image is atpresent observed by a sensor or to previously measure the ambient lightby the user by using an illumination photometer, a luminance meter, orthe like and to input the measured value to the signal conversion device16. It is also possible to use a method whereby several selection itemshave already been made and a proper value that is closest to the presentenvironment is selected among them.

By calculating white in the observation image from the ambient lightinformation obtained and the well-known reflectance of the paper and bychanging the background color of the monitor so that the luminance ofthe background color is lower than that of such white, both of thecolors can be matched.

The invention is not limited to the above embodiment. For example, theinvention can be applied to the color signal conversions of variousinput/output equipment. Namely, the invention can be used in every imageprocessing apparatus for performing the color signal conversion.

It will be obviously understood that the monitor display is not limitedto the CRT display but can also use a liquid crystal display.

According to the embodiment 3 and its modification as described above,in the correction to match the light source color and the observationcolor of the object color, the reference white is calculated on thebasis of not only the ambient light but also the background color incase of observing the image and the whole image is converted inaccordance with the calculated reference white. Therefore, theobservation color of the display image can be also matched to adifferent background color.

By forcedly setting the background color to a predetermined color, theobservation color can be more accurately matched.

By setting the luminance of the background color to be lower than thatof white of the image (white in the print image), both of the colors canbe matched.

By performing the color temperature conversion by reference whitesuitable for the observation environment, the color tones can bepreferably matched.

A highly-accurate color matching can be provided on the basis of anapplication of the user.

<Other embodiments>

The invention can be applied to a system constructed by a plurality ofequipment (for example, a host computer, an interface equipment, areader, a printer, or the like) or can also be applied to an apparatuscomprising one equipment (for example, a copying apparatus or afacsimile apparatus).

An invention embodied by a method whereby program codes of a software torealize the functions of the embodiment are supplied to a computer in anapparatus or system connected to various devices so as to make thedevices operative in order to realize the functions of the foregoingembodiments and the various devices are operated in accordance with theprograms stored in the computer (CPU or MPU) of the system or apparatusis also included in the scope of the invention.

In such a case, the program codes themselves of the software realize thefunctions of the foregoing embodiments and the program codes themselvesand means for supplying the program codes to the computer, for example,a memory medium in which the program codes have been stored constructthe invention.

As such a memory medium to store the program codes, for example, it ispossible to use a floppy disk, a hard disk, an optical disk, amagnetooptic disk, a CD-ROM, a magnetic tape, a non-volatile memorycard, an ROM, or the like can be used.

It will be obviously understood that the program codes are included inthe embodiments of the invention even in not only a case where thefunctions of the foregoing embodiments are realized by executing thesupplied program codes by the computer but also a case where thefunctions of the foregoing embodiments are realized in cooperation withthe OS (operating system) by which the program codes operate in thecomputer or another application software or the like.

Further, it will be also obviously understood that the invention alsoincorporates a case where the supplied program codes are stored into amemory provided for a function expansion board of a computer or afunction expansion unit connected to a computer and, after that, a CPUor the like provided for the function expansion board or functionexpansion unit executes a part or all of the actual processes on thebasis of instructions of the program codes, and the functions of theforegoing embodiments are realized by the processes.

Although the present invention has been described above with respect tothe preferred embodiments, the invention is not limited to the foregoingembodiments, and many modifications and variations are possible withinthe spirit and scope of the appended claims of the invention.

1. An image processing apparatus comprising: input means for inputtinginput image data from a source device having a function for adjusting animage processing condition on a basis of an instruction of a user;converting means for converting the input image data to deviceindependent image data by using a profile of the source device; andsetting means for setting a standard condition included in the profileas an image processing condition of the source device, wherein theadjusted image processing condition corresponding to the instruction ofthe user is made invalid, and wherein the input image data subjected toconversion by said converting means is generated by the source device byusing the standard condition set by said setting means.
 2. An apparatusaccording to claim 1, wherein the standard condition corresponds to acondition used when the profile is prepared.
 3. An apparatus accordingto claim 1, wherein the source device is a display device, and whereinthe image processing condition includes any one of conditions relatingto gamma characteristic, contrast, brightness, color, and temperature.4. An apparatus according to claim 1, wherein said converting meansperforms a color matching process corresponding to the source device andan image output device, and wherein said converting means converts thedevice independent image data to image data for the image output deviceby using an output profile of the image output device, and furthercomprising: correction means for correcting the converted image data byusing the standard condition included in the output profile.
 5. Anapparatus according to claim 1, wherein the source device includescorrection means for correcting image data by using the standardcondition set by said setting means.
 6. An image processing apparatuscomprising: converting means for converting input image data by using asource profile of a source device and an output profile of an imageoutput device; output means for outputting the converted image data tothe image output device having a function for adjusting an image outputcondition on a basis of an instruction of a user; and setting means forsetting a standard condition included in the output profile as an imageoutput condition of the image output device, wherein the adjusted imageoutput condition corresponding to the instruction of the user is madeinvalid, and wherein the image output device processes the convertedimage data by using the standard condition set by said setting means. 7.An image processing method comprising: an input step, of inputting inputimage data from a source device having a function for adjusting an imageprocessing condition on a basis of an instruction of a user; aconverting step, of converting the input image data to deviceindependent image data by using a profile of the source device; and asetting step, of setting a standard condition included in the profile asan image processing condition of the source device, wherein the adjustedimage processing condition corresponding to the instruction of the useris made invalid, and wherein the input image data subjected toconversion in said converting step is generated by the source device byusing the standard condition set in said setting step.
 8. A recordingmedium to store a program to execute an image processing method, saidprogram comprising: code for an inputting step, of inputting input imagedata from a source device having a function for adjusting an imageprocessing condition on the basis of an instruction of a user; code fora converting step, of converting the input image data to deviceindependent image data by using a profile of the source device; and codefor a setting step, of setting a standard condition included in theprofile as an image processing condition of the source device, whereinthe adjusted image processing condition corresponding to the instructionof the user is made invalid, and wherein the input image data subjectedto conversion by said converting code is generated by the source deviceby using the standard condition set by said setting code.
 9. An imageprocessing method comprising: a converting step, of converting inputimage data by using a source profile of a source device and an outputprofile of an image output device; an output step, of outputting theconverted image data to the image output device having a function foradjusting an image output condition on the basis of an instruction of auser; and a setting step, of setting a standard condition included inthe output profile as an image output condition of the image outputdevice, wherein the adjusted image output condition corresponding to theinstruction of the user is made invalid, and wherein the image outputdevice processes the converted image data by using the standardcondition set in said setting step.
 10. A recording medium to store aprogram to execute an image processing method, said method comprising:code for a converting step, of converting input image data by using asource profile of a source device and an output profile of an imageoutput device; code for an output step, of outputting the convertedimage data to the image output device having a function for adjusting animage output condition on the basis of an instruction of a user; andcode for a setting step, of setting a standard condition included in theoutput profile as an image output condition of the image output device,wherein the adjusted image output condition corresponding to theinstruction of the user is made invalid, and wherein the image outputdevice processes the converted image data by using the standardcondition set by said setting code.
 11. An image processing apparatuscomprising: an input unit, adapted to input image data from a sourcedevice having a function for adjusting an image processing condition ona basis of an instruction of a user; a converting unit, adapted toconvert the input image data to device independent image data by using aprofile of the source device; and a setting unit, adapted to set astandard condition included in the profile as an image processingcondition of the source device, wherein the adjusted image processingcondition corresponding to the instruction of the user is made invalid,and wherein the input image data subjected to conversion by saidconverting unit is generated by the source device by using the standardcondition set by said setting unit.
 12. An image processing apparatuscomprising: a converting unit, adapted to convert input image data byusing a source profile of a source device and an output profile of animage output device; an output unit, adapted to output the convertedimage data to the image output device having a function for adjusting animage output condition on a basis of an instruction of a user; and asetting unit, adapted to set a standard condition included in the outputprofile as an image output condition of the image output device, whereinthe adjusted image output condition corresponding to the instruction ofthe user is made invalid, and wherein the image output device is adaptedto process the converted image data by using the standard condition setby said setting unit.